As compared with silicon semiconductors currently most widely used, a semiconductor layer itself that is made of a wide band gap semiconductor can withstand a significantly Mai electric field. Meanwhile, application of a relatively high electric field is more likely to cause, irrespective of the type of the semiconductor material, creeping discharge resulting from electric field concentration at the termination portion surrounding element portion on a semiconductor substrate. Therefore, countermeasures against creeping discharge are particularly required when a wide band gap semiconductor is used. Creeping discharge can be suppressed by increasing a dielectric constant of an interlayer insulation film. For example, Japanese Patent No. 4796665 (PTD 1) discloses that the relative dielectric constant of the interlayer insulation film is set at 20 or more.